The present invention relates to a client system such as a browser apparatus, a personal computer or the like which receives a World Wide Web (WWW) service. More particularly, the present invention relates to a cache mechanism in which a copy of information acquired from a network is held and the held copy is subjected to display or the like at the time of second and subsequent accesses, thereby shortening a time required up to display or the like and reducing a load imposed on the network. Also, the present invention relates to the pre-reading and caching of information having a high possibility that a user browses the information. Further, the present invention relates to a processing which is performed in the case where a cache is constituted in a removable storage medium and when the storage medium is removed.
In recent years, social attention to a World Wide Web (WWW) service through the Internet has been given as a typical example of utilization of the Internet. The acquisition and browsing of information opened to the public in all the world have become possible by connecting a household personal computer to the Internet through a telephone line or the like and operating a WWW browser program. In this case, a time from the designation of information to be acquired to the enabling of actual browsing of the information may be taken due to the insufficiency of the band of a communication line. In order to cover or hide this delay time, there is known a method for constitution of a cache storage for browse information in which a copy of information having once been browsed is stored in a secondary memory device (for example, a hard disk drive or the like) and the stored copy is retrieved from the secondary memory device at the time of second and subsequent browsings.
Generally, in the case where information is retrieved through a network, the problem of a delay time arises. A method of covering this delay by use of a cache memory has been disclosed JP-A-62-6355 filed in Japan.
Also, JP-A-63-201743 filed in Japan has disclosed a method in which the efficiency is improved by using a cache for the access of information through a network though a point of the disclosed invention lies in means for ensuring the effectiveness of the cache.
If a WWW browser program or browser apparatus provided with a cache is used, it is possible to cover delay times for second and subsequent accesses.
However, in the case where a user utilizes another browser apparatus, it is not absolutely possible to enjoy a merit caused by the above effect. Now assume that there are two or first and second browser apparatuses having a similar specification. Even if a user having browsed certain information by use of the first browser apparatus moves to the second browser apparatus and tries to browse the same information, there is no assurance that the information is included in a cache of the second browser apparatus. In the user""s point of view, information having once been browsed by the user himself or herself should be displayed immediately at the time of second browsing even if the other browser apparatus is used. This is a first problem to be solved by the present invention.
In a WWW browser, it is general that the successive tracing (or jumping) of information is made by means of hyperlink. A character string set with hyperlink is called an anchor. When the jumping by the hyperlink is made by designating, a delay time for network access is taken in the case where information at the destination of jumping is information which has not yet been inspected. When the connection is made using a low-speed line such as a telephone line, there may arise the case where a comfortable browsing work cannot be conducted. This is a second problem to be solved by the present invention.
In order to solve the first problem, a memory device including a removable storage medium stored with information is used. In the case where this storage medium is removed, there is a write processing to be completed prior to the removal. In the case where a user operates an eject button with which the memory device is provided, it is not always that the completion of the write processing is ensured. This is a second problem to be solved by the present invention.
The first problem can be solved by a construction with which a user is allowed to carry a cache of information having been browsed by the user himself or herself. A memory device including a removable storage medium stored with information may be used so that a cache is constituted in the removal storage medium. In the case where an access time of this memory device is longer than that of another secondary memory device, for example, a hard disk drive, those memories are used in combination to constitute the cache. It is constructed such that when the storage medium is pulled out or a browser program is completed, all of information stored in the cache inclusive of the other secondary memory device are written into the storage medium. By carrying such a storage medium, the user can restart a browsing work smoothly. In an extreme case, the browsing is possible even by a browser apparatus connected to no network so long as it concerns the browsing of information recorded in such a storage medium.
In order to solve the second problem, information having a high possibility of designation by the user is stored in the cache beforehand through pre-reading. There is a high possibility that the user designates any one of anchors buried in browse information. Over all, provided that the possibility of designation of an anchor being displayed presently in a display window is high, information at the destination of hyperlink for the anchor being displayed is stored into the cache.
The third problem can be solved by a construction in which in the case where the user operates an eject button, the ejection of the storage medium is not immediately conducted but a routine for performing a write processing required on the system side is started so that after the write processing is completed, a signal indicating the instruction for or permission of ejection of the storage medium is given from the system side to the memory device.
More particularly, in a terminal apparatus, a storage medium for storing information from a network as cache data is made freely detachable. Also, there is provided means for recording the information as cache data into a secondary memory device other than the storage medium. Further, there is provided means for recording the cache data into the storage medium as cache data which is also usable in another terminal apparatus. Furthermore, a first directory table for associating an address of the information on a network and an address of the information on the storage medium stored as the cache data in the storage medium is provided in the storage medium, a second directory table for associating an address of the information on the network and an address of the information on the secondary memory device stored as the cache data in the secondary memory device is provided in the secondary memory device, and there is provided means for making the search of cache data by use of a third directory which is generated by merging the first directory table and the second directory table with the address of the information on the network used a key and is provided with a field for the address on the storage medium and a field for the address on the secondary memory device.
Also, in a method for information access from a terminal apparatus used in a manner connected to a network, the method comprises a step of writing a copy of information from a network into a storage medium which is freely detachable from the terminal apparatus, a step of first making access to the storage medium when the terminal apparatus makes access to the information, and a step of acquiring the information through the network in the case where there is not the information in the storage medium.
Also, in a recording medium freely detachable from a terminal apparatus, the recording medium has a portion in which a program executed by the terminal apparatus is recorded, and a portion in which information from the network to which the terminal apparatus is connected is recorded as cache data by the program. Otherwise, in a recording medium freely detachable from a terminal apparatus, the recording medium has a portion recorded with a program by which information from the network to which the terminal apparatus is connected is recorded as cache data into a recording medium freely detachable from the terminal apparatus.
Also, in a method for information acquisition from a terminal apparatus which acquires information from a network, the method comprises a step of applying the order of preference to anchors displayed in a display window of the terminal apparatus, and a step of acquiring, before a user makes the designation of an anchor, information at the destination of link indicated by the anchor through the network in accordance with the order of preference. The method further comprises a step of interchanging, the display attribute of an anchor the acquisition of which starts before the user makes the designation of an anchor, the display attribute of an anchor the acquisition of which has been completed, and the display attribute of an anchor the acquisition of which has not yet started.
Also, in a method for information access from a terminal apparatus which acquires information from a network, the method comprises a step of applying the order of preference to anchors displayed in a display window of the terminal apparatus, a step of acquiring, before a user makes the designation of an anchor, information at the destination of link indicated by the anchor through the network in accordance with the order of preference, and a step of recording the information from the network as cache data into a recording medium which is freely detachable from the terminal apparatus.
Also, in a memory device including a removable storage medium stored with information, when the indication of ejection of the storage medium is given from a user to the memory device, a write processing for the storage medium is performed in the case where information to be recorded in the storage medium exists in the memory device and a system to which the memory device is connected, and an instruction for or the permission of ejection of the storage medium is given from the system to the memory device after the write processing is completed.
Also, in a system in which the combination of a memory device including a removable storage medium stored with information and another secondary memory device is used as a cache storage for storing a copy of information acquired through a network and the cache storage is controlled in such a manner that it is also held in the storage medium, it is constructed so that when the indication of ejection of the storage medium is given from a user to the memory device, a write processing for the storage medium is performed in the case where information to be recorded in the storage medium exists in the cache storage, and an instruction for or the permission of ejection of the storage medium is given from the system to the memory device after the write processing is completed.